Remove "tree->entries" tree-entry list from tree parser

Instead, just use the tree buffer directly, and use the tree-walk
infrastructure to walk the buffers instead of the tree-entry list.

The tree-entry list is inefficient, and generates tons of small
allocations for no good reason. The tree-walk infrastructure is
generally no harder to use than following a linked list, and allows
us to do most tree parsing in-place.

Some programs still use the old tree-entry lists, and are a bit
painful to convert without major surgery. For them we have a helper
function that creates a temporary tree-entry list on demand.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>

diff --git a/builtin-ls-tree.c b/builtin-ls-tree.c
index 48385d5..b8d0d88 100644 (file)
--- a/builtin-ls-tree.c
+++ b/builtin-ls-tree.c
@@ -53,7 +53,7 @@ static int show_recursive(const char *base, int baselen, const char *pathname)
        }
 }
 
-static int show_tree(unsigned char *sha1, const char *base, int baselen,
+static int show_tree(const unsigned char *sha1, const char *base, int baselen,
                     const char *pathname, unsigned mode, int stage)
 {
        int retval = 0;

diff --git a/builtin-read-tree.c b/builtin-read-tree.c
index 67492bf..480e6ed 100644 (file)
--- a/builtin-read-tree.c
+++ b/builtin-read-tree.c
@@ -165,7 +165,7 @@ static int unpack_trees_rec(struct tree_entry_list **posns, int len,
                                struct tree *tree = lookup_tree(posns[i]->sha1);
                                any_dirs = 1;
                                parse_tree(tree);
-                               subposns[i] = tree->entries;
+                               subposns[i] = create_tree_entry_list(tree);
                                posns[i] = posns[i]->next;
                                src[i + merge] = &df_conflict_entry;
                                continue;
@@ -370,7 +370,7 @@ static int unpack_trees(merge_fn_t fn)
        if (len) {
                posns = xmalloc(len * sizeof(struct tree_entry_list *));
                for (i = 0; i < len; i++) {
-                       posns[i] = ((struct tree *) posn->item)->entries;
+                       posns[i] = create_tree_entry_list((struct tree *) posn->item);
                        posn = posn->next;
                }
                if (unpack_trees_rec(posns, len, "", fn, &indpos))

diff --git a/builtin-rev-list.c b/builtin-rev-list.c
index 94f520b..6e2b898 100644 (file)
--- a/builtin-rev-list.c
+++ b/builtin-rev-list.c
@@ -113,7 +113,7 @@ static struct object_list **process_tree(struct tree *tree,
                                         const char *name)
 {
        struct object *obj = &tree->object;
-       struct tree_entry_list *entry;
+       struct tree_desc desc;
        struct name_path me;
 
        if (!revs.tree_objects)
@@ -128,16 +128,22 @@ static struct object_list **process_tree(struct tree *tree,
        me.up = path;
        me.elem = name;
        me.elem_len = strlen(name);
-       entry = tree->entries;
-       tree->entries = NULL;
-       while (entry) {
-               struct tree_entry_list *next = entry->next;
-               if (entry->directory)
-                       p = process_tree(lookup_tree(entry->sha1), p, &me, entry->name);
+
+       desc.buf = tree->buffer;
+       desc.size = tree->size;
+
+       while (desc.size) {
+               unsigned mode;
+               const char *name;
+               const unsigned char *sha1;
+
+               sha1 = tree_entry_extract(&desc, &name, &mode);
+               update_tree_entry(&desc);
+
+               if (S_ISDIR(mode))
+                       p = process_tree(lookup_tree(sha1), p, &me, name);
                else
-                       p = process_blob(lookup_blob(entry->sha1), p, &me, entry->name);
-               free(entry);
-               entry = next;
+                       p = process_blob(lookup_blob(sha1), p, &me, name);
        }
        free(tree->buffer);
        tree->buffer = NULL;

diff --git a/fetch.c b/fetch.c
index f7f8902..d9fe41f 100644 (file)
--- a/fetch.c
+++ b/fetch.c
@@ -41,16 +41,22 @@ static int process_tree(struct tree *tree)
        if (parse_tree(tree))
                return -1;
 
-       entry = tree->entries;
-       tree->entries = NULL;
+       entry = create_tree_entry_list(tree);
        while (entry) {
                struct tree_entry_list *next = entry->next;
-               if (process(entry->item.any))
-                       return -1;
-               free(entry->name);
+
+               if (entry->directory) {
+                       struct tree *tree = lookup_tree(entry->sha1);
+                       process_tree(tree);
+               } else {
+                       struct blob *blob = lookup_blob(entry->sha1);
+                       process(&blob->object);
+               }
                free(entry);
                entry = next;
        }
+       free(tree->buffer);
+       tree->buffer = NULL;
        return 0;
 }
 

diff --git a/fsck-objects.c b/fsck-objects.c
index ed2eb27..42778e8 100644 (file)
--- a/fsck-objects.c
+++ b/fsck-objects.c
@@ -11,6 +11,7 @@
 #include "cache-tree.h"
 
 #define REACHABLE 0x0001
+#define SEEN      0x0002
 
 static int show_root = 0;
 static int show_tags = 0;
@@ -161,7 +162,7 @@ static int fsck_tree(struct tree *item)
        struct tree_entry_list *entry, *last;
 
        last = NULL;
-       for (entry = item->entries; entry; entry = entry->next) {
+       for (entry = create_tree_entry_list(item); entry; entry = entry->next) {
                if (strchr(entry->name, '/'))
                        has_full_path = 1;
                has_zero_pad |= entry->zeropad;
@@ -205,7 +206,6 @@ static int fsck_tree(struct tree *item)
        }
        if (last)
                free(last);
-       item->entries = NULL;
        free(item->buffer);
        item->buffer = NULL;
 
@@ -277,6 +277,9 @@ static int fsck_sha1(unsigned char *sha1)
        struct object *obj = parse_object(sha1);
        if (!obj)
                return error("%s: object not found", sha1_to_hex(sha1));
+       if (obj->flags & SEEN)
+               return 0;
+       obj->flags |= SEEN;
        if (obj->type == blob_type)
                return 0;
        if (obj->type == tree_type)

diff --git a/http-push.c b/http-push.c
index f492a5d..72ad89c 100644 (file)
--- a/http-push.c
+++ b/http-push.c
@@ -1704,6 +1704,7 @@ static struct object_list **process_blob(struct blob *blob,
                return p;
 
        obj->flags |= SEEN;
+       name = strdup(name);
        return add_object(obj, p, path, name);
 }
 
@@ -1713,7 +1714,7 @@ static struct object_list **process_tree(struct tree *tree,
                                         const char *name)
 {
        struct object *obj = &tree->object;
-       struct tree_entry_list *entry;
+       struct tree_desc desc;
        struct name_path me;
 
        obj->flags |= LOCAL;
@@ -1724,21 +1725,30 @@ static struct object_list **process_tree(struct tree *tree,
                die("bad tree object %s", sha1_to_hex(obj->sha1));
 
        obj->flags |= SEEN;
+       name = strdup(name);
        p = add_object(obj, p, NULL, name);
        me.up = path;
        me.elem = name;
        me.elem_len = strlen(name);
-       entry = tree->entries;
-       tree->entries = NULL;
-       while (entry) {
-               struct tree_entry_list *next = entry->next;
-               if (entry->directory)
-                       p = process_tree(lookup_tree(entry->sha1), p, &me, entry->name);
+
+       desc.buf = tree->buffer;
+       desc.size = tree->size;
+
+       while (desc.size) {
+               unsigned mode;
+               const char *name;
+               const unsigned char *sha1;
+
+               sha1 = tree_entry_extract(&desc, &name, &mode);
+               update_tree_entry(&desc);
+
+               if (S_ISDIR(mode))
+                       p = process_tree(lookup_tree(sha1), p, &me, name);
                else
-                       p = process_blob(lookup_blob(entry->sha1), p, &me, entry->name);
-               free(entry);
-               entry = next;
+                       p = process_blob(lookup_blob(sha1), p, &me, name);
        }
+       free(tree->buffer);
+       tree->buffer = NULL;
        return p;
 }
 

diff --git a/revision.c b/revision.c
index 8d70a6f..c51ea83 100644 (file)
--- a/revision.c
+++ b/revision.c
@@ -63,8 +63,7 @@ void mark_tree_uninteresting(struct tree *tree)
                return;
        if (parse_tree(tree) < 0)
                die("bad tree %s", sha1_to_hex(obj->sha1));
-       entry = tree->entries;
-       tree->entries = NULL;
+       entry = create_tree_entry_list(tree);
        while (entry) {
                struct tree_entry_list *next = entry->next;
                if (entry->directory)

diff --git a/tree.c b/tree.c
index 88f8fd5..db6e59f 100644 (file)
--- a/tree.c
+++ b/tree.c
@@ -151,22 +151,65 @@ struct tree *lookup_tree(const unsigned char *sha1)
        return (struct tree *) obj;
 }
 
-int parse_tree_buffer(struct tree *item, void *buffer, unsigned long size)
+static int track_tree_refs(struct tree *item)
 {
+       int n_refs = 0, i;
+       struct object_refs *refs;
        struct tree_desc desc;
-       struct tree_entry_list **list_p;
-       int n_refs = 0;
 
+       /* Count how many entries there are.. */
+       desc.buf = item->buffer;
+       desc.size = item->size;
+       while (desc.size) {
+               n_refs++;
+               update_tree_entry(&desc);
+       }
+
+       /* Allocate object refs and walk it again.. */
+       i = 0;
+       refs = alloc_object_refs(n_refs);
+       desc.buf = item->buffer;
+       desc.size = item->size;
+       while (desc.size) {
+               unsigned mode;
+               const char *name;
+               const unsigned char *sha1;
+               struct object *obj;
+
+               sha1 = tree_entry_extract(&desc, &name, &mode);
+               update_tree_entry(&desc);
+               if (S_ISDIR(mode))
+                       obj = &lookup_tree(sha1)->object;
+               else
+                       obj = &lookup_blob(sha1)->object;
+               refs->ref[i++] = obj;
+       }
+       set_object_refs(&item->object, refs);
+       return 0;
+}
+
+int parse_tree_buffer(struct tree *item, void *buffer, unsigned long size)
+{
        if (item->object.parsed)
                return 0;
        item->object.parsed = 1;
        item->buffer = buffer;
        item->size = size;
 
-       desc.buf = buffer;
-       desc.size = size;
+       if (track_object_refs)
+               track_tree_refs(item);
+       return 0;
+}
+
+struct tree_entry_list *create_tree_entry_list(struct tree *tree)
+{
+       struct tree_desc desc;
+       struct tree_entry_list *ret = NULL;
+       struct tree_entry_list **list_p = &ret;
+
+       desc.buf = tree->buffer;
+       desc.size = tree->size;
 
-       list_p = &item->entries;
        while (desc.size) {
                unsigned mode;
                const char *path;
@@ -186,29 +229,19 @@ int parse_tree_buffer(struct tree *item, void *buffer, unsigned long size)
                entry->next = NULL;
 
                update_tree_entry(&desc);
-               n_refs++;
                *list_p = entry;
                list_p = &entry->next;
        }
+       return ret;
+}
 
-       if (track_object_refs) {
-               struct tree_entry_list *entry;
-               unsigned i = 0;
-               struct object_refs *refs = alloc_object_refs(n_refs);
-               for (entry = item->entries; entry; entry = entry->next) {
-                       struct object *obj;
-
-                       if (entry->directory)
-                               obj = &lookup_tree(entry->sha1)->object;
-                       else
-                               obj = &lookup_blob(entry->sha1)->object;
-                       refs->ref[i++] = obj;
-               }
-
-               set_object_refs(&item->object, refs);
+void free_tree_entry_list(struct tree_entry_list *list)
+{
+       while (list) {
+               struct tree_entry_list *next = list->next;
+               free(list);
+               list = next;
        }
-
-       return 0;
 }
 
 int parse_tree(struct tree *item)

diff --git a/tree.h b/tree.h
index a27bae4..c7b5248 100644 (file)
--- a/tree.h
+++ b/tree.h
@@ -20,9 +20,11 @@ struct tree {
        struct object object;
        void *buffer;
        unsigned long size;
-       struct tree_entry_list *entries;
 };
 
+struct tree_entry_list *create_tree_entry_list(struct tree *);
+void free_tree_entry_list(struct tree_entry_list *);
+
 struct tree *lookup_tree(const unsigned char *sha1);
 
 int parse_tree_buffer(struct tree *item, void *buffer, unsigned long size);